MERV stands for the Minimum Efficiency Reporting Value. This measurement scale was designed to rate the effectiveness of air filters……their particle removal capability, resistance to airflow, and the expected operating life. MERV ratings are usually valued between 1 and 16 although they can go as high as 20 (however those are usually for more commercial/industrial systems). Residential air filters tend to fall more between the ratings of 5 and 13.
The United States Environmental Protection Agency states that “Medium efficiency filters with a MERV of 5 to 13 are reasonably efficient at removing small to large airborne particles. Filters with a MERV between 7 and 13 are likely to be nearly as effective as true HEPA filters at controlling most airborne indoor particles.” The EPA adds that “medium efficiency air filters are generally less expensive than HEPA filters, and allow quieter HVAC fan operation and higher airflow rates than HEPA filters since they have less airflow resistance.”
We’ve all heard of HEPA (High Efficiency Particulate Air) filters before however, most homes are not capable of having whole-house HEPA filtration systems installed without having extensive modification done. That being said, keep in mind the EPA’s recommendation for filters with a MERV rating from 7 to 13.
So next time you are in the store shopping for a replacement air filter, remember to consider MERV when you make your choice.